Links

Classifications

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating

A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current

A61B18/1206—Generators therefor

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating

A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current

A61B18/14—Probes or electrodes therefor

A61B18/1442—Probes having pivoting end effectors, e.g. forceps

A61B18/1445—Probes having pivoting end effectors, e.g. forceps at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B2018/00315—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body for treatment of particular body parts

A61B2018/00345—Vascular system

A61B2018/00404—Blood vessels other than those in or around the heart

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B2018/00571—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body for achieving a particular surgical effect

A61B2018/00601—Cutting

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B2018/00571—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body for achieving a particular surgical effect

A61B2018/00607—Coagulation and cutting with the same instrument

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B2018/00571—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body for achieving a particular surgical effect

A61B2018/0063—Sealing

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B2018/00636—Sensing and controlling the application of energy

A61B2018/00696—Controlled or regulated parameters

A61B2018/00702—Power or energy

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B2018/00636—Sensing and controlling the application of energy

A61B2018/00773—Sensed parameters

A61B2018/00875—Resistance or impedance

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61B—DIAGNOSIS; SURGERY; IDENTIFICATION

A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body

A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating

A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current

A61B18/1206—Generators therefor

A61B2018/124—Generators therefor switching the output to different electrodes, e.g. sequentially

Abstract

The invention relates to an electrosurgical instrument comprising two branches that are interconnected by an articulation and that can be actuated to open and close in the manner of a clamping tool, separator or cutting tool. The instrument also comprises electrode parts on distal ends of the branches for grasping tissue and for conducting a coagulation current through the latter, said electrodes being electrically insulated in relation to one another, in addition to current supply devices for supplying the coagulation current to the electrode parts. Said electrosurgical instrument is configured in such a way that an operation requiring in particular several steps can be carried out in a simple manner in an optimised sequence. To achieve this, a cutting section that is designed as a cutting electrode is configured on at least one electrode part, in such a way that the electrode part comprises the cutting section and a coagulation section. In addition, the instrument is provided with a control unit for controlling the HF current, in such a way that a cutting current, which differs from the coagulation current, is supplied to at least the cutting section when a threshold value, which identifies a characteristic of the captured tissue, has been reached.

Description

The electrosurgical instrument

description

The invention relates to an electrosurgical instrument according to the preamble of claim 1.

Electrosurgical instruments are used for many years in the high-frequency surgery to coagulate biological tissue and / or cut.

Here, a high-frequency current is passed through the tissue to be treated, so that it changes due to protein coagulation and dehydration. The tissue contracts in such together, that the vessels are closed and bleeding can be stopped. A subsequent increase in current density causes an explosive vaporization of tissue fluid, and a rupture of the cell membranes, the

Tissue is completely severed. Processes of this type have, compared to a purely mechanical cut the advantage of hemostasis along the cut edges.

The use of bipolar instruments is becoming increasingly important as smaller currents than with monopolar instruments are needed. It is of advantage in particular that the current path between the electrode parts of bipolar instruments is calculated and does not long distances runs through the body of the patient.

(Bipolar instruments have substantially two hingedly interconnected clamping parts, being provided at their proximal ends gripping devices for the handling of the clamping parts. Are located at distal ends of the clamping parts electrode members for grasping tissue and for conducting a coagulation current through the tissue. The by a RF generator generated RF current is conducted via current supply means to the electrode parts of the bipolar instrument.

When using the above-described bipolar instruments cutting instruments must be used now finally to sever the coagulated tissue to a coagulation process. The incision is carried out either with a surgical scissors or a RF cutting instrument. However, the use of different instruments requires an interruption of surgery and delay this addition unnecessary.

To counter this disadvantage, multifunctional instruments are now designed at least for the coagulation and for cutting. Such an instrument is known for example from DE 199 15 060 AI, in which various working devices such. B. tongs, hooks or Ultra schalleinrichtun- gene and electrodes for cutting or coagulation via actuators are operable. A control unit permits the successive execution intended work steps.

However, the embodiment of a multifunctional instrument described here has the disadvantage that after coagulation and cutting, such as are two different, consecutively executed time-actions, even if the steps can be performed by a single instrument. A first operation must therefore deliberately finished and a second operation are deliberately started again. Between the tasks to be performed at least one action, namely to enable the multi-functional tool for the next task. This also unnecessarily delayed the course of the operation. In addition, errors can occur when the activation of a process in terms of setting the appropriate operating parameters such. B. a suitable RF current occur. .

Known multifunction tools of the type described above also have electrically insulated from each other, respectively provided for coagulating and for cutting poles, so that there are for the instrument relatively large dimensions. This limits the freedom of movement of the surgeon at the surgical area significantly and thus limits the application of the known instruments.

The invention is therefore based on the object, an electrosurgical instrument of the type referred to in such a way that a particular procedure several passages requiring operation in the simplest way and with optimized sequence is feasible.

This object is achieved by an electrosurgical instrument according to claim. 1 In particular, the object is achieved by an electrosurgical instrument comprising two branches articulated to one another, which can be actuated for opening or closing according to a clamping, spreading or cutting tool. Further, the instrument includes electrode parts at distal ends of the branches to the

Grasping tissue and for conducting a coagulation current through the tissue to coagulation thereof, which are electrically insulated from each other, and current supply devices for feeding the coagulating current to the electrode parts. a is laid out as a cutting electrode, the cutting portion is fixed to the instrument further at least at one electrode part is designed so that the electrode part has the cutting section and a coagulation section. In addition, a control unit for controlling the HF current is provided such that on reaching a characteristic properties of the tissue detected threshold the cutting portion, a cutting current is supplied to at least that is different to the coagulation current.

An essential point of the invention lies in the fact that a cutting portion being disposed at a designed for the coagulation electrode member that it acts at a suitable time, that is when a specific operation stage as a cutting electrode. The surgeon is therefore the transition from a

Coagulation not be charged in a subsequent cutting phase with decision tasks. At the same optimum operating parameters, such are. As the correct amperage can be generated without the surgeon must adjust this automatically via the voltage on the RF generator. Thus the timing between the individual operation phases and the need for RF power are optimally matched. The intervention is therefore feasible, taking utmost elimination of sources of error.

Preferred developments of the invention are specified in the subclaims.

In a first preferred guide of the control unit switching devices are associated form, which detect the threshold value as a defined distance between the branches, so that the cutting current is supplied depending on the distance. Once a predetermined distance between the sectors, that is, below between the electrode parts, then a supply of the cutting current at least at the cutting portion. The switching devices to conduct upon actuation of a signal to the control unit further, which causes a high-frequency generator, that the cutting section, a corresponding cutting current is supplied. The distance is used as indication that a cutting operation can be performed, that is, the electrode members have a spacing from one another, in which a cutting is possible at all. The distance between the electrode parts is defined about the level of the adjusted RF voltage.

The switching devices are advantageously provided on at least one of the sectors and / or on a arranged at least on one of the branches spacer. This is advantageous because the distance then detected directly by the switching means and the cutting operation can be triggered at the same time from these.

In. a preferred embodiment, the switching devices formed as a push-button switch. This is then preferably attached to the spacer of a sector, so that upon contact of the switch by the opposite sector and thus upon reaching the threshold value - here the defined distance between the electrode parts - the cutting current is supplied to the cutting portion. This is a particularly simple embodiment to trigger an inexpensive manner when falling below the predetermined distance between the electrode parts of the cutting operation.

In a further preferred guiding the switching devices are configured as a proximity switch form. These have the advantage of not touching the branches are provided ow and the mechanism is therefore less susceptible to wear and works precisely.

Advantageously, the non-contact switches are then, for example as

formed proximity switch or as a reed contact. Z. B. mounted a reed contact on one branch and a magnet on the opposing branch, so switches the reed switch when the magnet to the reed contact having a predetermined distance. Similarly, a proximity sensor, such as an inductive proximity switch operates. The attached on one sector proximity switches on, as soon as a arranged on the opposite ends cherish industry metallic object, eddy currents generated in an alternating electromagnetic field of the proximity switch. In a switch of the type described herein, the operating distance may preferably be defined by the sometimes introduced into the alternating field metal object.

Advantageously, the control unit is assigned a device for resistance measurement which detects the threshold value as the ohmic resistance of the tissue so that the cutting current is fed depending on the ohmic resistance. The resistance measurement of tissue allows the determination of a precise point in time from when a cutting process can be started. Once in the tissue, a defined resistance is achieved due to the operation path, causes the control unit that the cutting portion of the corresponding cutting current is supplied. This process is extremely reliable because of changing by the coagulation tissue resistance is a precise indication as to when you can start with a cutting.

In a further preferred guide of the control unit, an arc monitor and / or current monitor is associated form, which detect the threshold value as optimal Koagulationsendzeitpunkt, so that the cutting current is supplied depending on the Koagulationsendzeitpunktes. That is, the cutting current is supplied to at least the cutting portion when the coagulation is terminated due to the supplied by the corresponding monitor signal. In order for the supply of cutting current is advantageously an ideal for the course of the operation time. The operations of the current monitor and arc monitor are described for example in EP 0253012 Bl detail.

Preferably, the cutting portion is formed of the at least one electrode part as one with respect to the coagulation section at least one electrode part tapered region. Here coagulation section and cutting section can embellish an integrally formed electrode or the two regions are arranged independently. The tapered design of the cutting portion allows a required for the cutting of tissue increasing the current density at the cutting portion. That the coagulation section and the cutting section integrally forming electrode part, during a coagulation process over its entire surface area, ie both the surface area of ​​the Koagulationsabschnittes and over the surface region of the cutting section, act as coagulation, while the rejuvenated designed cutting section stands alone for a later cutting available , When formed separately areas for coagulating and cutting these, both in combination and separately from each other can be used. The smaller, formed as a cutting portion surface area, an adequate cutting current via the power supply means is supplied according to the above embodiments. Thus, one and the same instrument both for coagulation and for cutting must be used.

In a preferred embodiment of the cutting edge portion is formed as having a substantially triangular cross-section of the at least one electrode part. A triangular cross-section allows the gradual transition from a large area of ​​the electrode portion to the edge-shaped taper. The smooth transition is particularly suitable to use the entire electrode part with adequate tissue thickness as coagulation and use in an advanced operational stage, the cutting section for cutting alone.

Advantageously, the cutting portion is formed as an edge with a substantially circular cross-section of the at least one electrode part. In this embodiment, there is a relatively large electrode area for the coagulation available during configured as edge

Cutting portion is negligible weight at sufficiently large tissue thickness. In an advanced stage of operation, however, and with sufficient closeness to entertain Direction electrode parts of the electrosurgical instrument, the current density can be increased in such a way, due to the edge-shaped configuration of the cutting portion, that a cutting operation is made possible.

Another solution provides to form the cutting portion is substantially spherical, the at least one electrode part. Thus, the cutting face can hold larger and carry a correspondingly large cut. The inventive solution provides that the cutting portion edge-, needle or loop is shaped. This corresponds to other conventional forms of cutting electrodes, so that the cutting with the usual instruments for the respective application is feasible.

In a preferred of the cutting portion is formed respectively at opposite electrode portions cherish guide form. Due to the designed for cutting sections particularly precise cutting action is attainable here because the current density can be increased at both electrode parts.

However, the cutting portion can also be arranged outside the Koagulationsabschnittes, ie be formed separately from this, as already mentioned above. Advantageously, the cutting portion is then formed by means of positioning devices as a component movable relative to the coagulation section on the latter. The cutting portion can be removed during a coagulation of the Koagulationsgebiet then, so here no undesirable cutting effects. When the threshold is reached, the cutting section can be or can be the cutting portions in the appropriate, bring required position for the cutting operation.

Preferably, the positioning means comprise a rotatably mounted in one of the limbs the two-armed lever having a first end and a second end, said first end for receiving the cutting portion and the second end intended to make contact with the opposite cherish ligand industry or provided on the opposite cherish ligand industry spacer is. If the connection of the second end with the opposing branch of the cutting portion in direction of the opposite electrode part is movable. The positioning means also comprise a return means so that the cutting portion after completion of the contacting is moved back into the starting position. Thus, it can immerse themselves in a particularly simple manner the cutting portion during the coagulation phase within the Koagulationsabschnittes, so here impairment of coagulation is prevented by the cutting section. Once in this case the threshold is reached and there is a contacting, the cutting portion rotates from its resting position. Feeding of the cutting current to the now disclosed cutting portion may for example take place via the switching means entprechend the above, are disposed on the spacer or at the second end of the lever and hefern a corresponding signal to the control unit. Due to the simple mechanical design such a multifunctional electrosurgical instrument is inexpensive and easy to manufacture. The positioning of the cutting portion is also independent of a manual force of the surgeon because the control unit is only activated due to the contact. Incidentally, a positioning device just described can also provide both industries.

A preferred embodiment provides that the first end of the two-armed lever a receiving device is mounted to the cutting section. Advantageous way proving to the cutting section can then remove temporary. This is

Advantageous if the cutting section is to be cleaned after an operation phase or when a cutting operation is not provided. Making it possible to disable the simplest way of cutting section.

A möghche implementation of the device is to form the cutting section as an integral part of the first end of the two-armed lever. Thus, the positioning device can be produced in a particularly simple manner.

A preferred embodiment provides that the return means for the lever arm is provided as in the positioning means having industry arranged spring element. A spring element is an easy-to-install and cost-effective component that always delivers hardly susceptible to wear the required function.

One inventive solution provides for the cutting section of an anti-

Adhesive coating and / or form of erosion-resistant material. The introduced into the tissue to be treated HF current caused due to the heat generation, not only the desired coagulation or cutting effects. Rather z can. particularly B. burning debris and blood on the electrode parts of the terminals so strong that the current flow is impaired. An anti adhesive coating reduces such pollution and should in particular be provided at the cutting portion jeweihgen. A layer of erosion-resistant material can also protect against wear due to the high power RF to the cutting portion.

The invention will be described with reference to embodiments which will be explained in detail with reference to the figures. Shown are

- Figure 1 is an electrode assembly in a first disclosed embodiment;.

- Figure 2 is an electrode arrangement in a second disclosed embodiment;.

- Fig. 3, an electrode assembly in a third disclosed embodiment;

- Figure 4 is an electrode assembly in a fourth embodiment;.

- Fig. 5 is a functional block diagram;

- Fig. 6 is a sectional view taken along line VI - VI of Figure 7 of an electrode arrangement in a fifth embodiment.

- Fig. 7 is a side view of the electrode arrangement of FIG. 6;

- Figure 8a shows a current-time diagram in which the variation of the current is shown in different operating modes;.

- Fig. 8b is a voltage-time diagram in which the variation of the voltage in different modes of operation according to FIG is shown. 8a.

In the following description, the same reference numerals are used for identical and identically acting parts. Fig. 1 to 3 show various disclosed embodiment, an array of opposed electrode portions 18, 19. In this case, an explicit cutting section 18a is formed only on an electrode part 18. It should be noted that this is schematic illustrations showing a front view ledighch the electrode parts 18, 19th The electrode members 18, 19 receiving electrosurgical instrument 10 is not shown.

The formation of the cutting portion 18a is ideally reached by a tapering of the respective electrode portion 18 so that the electrode part 18 has eventually a coagulation section 18b, and a cutting region, that is, the cutting portion 18a. The reduction of the electrode surface permits required for the cutting of tissue increasing the current density at the cutting portion 18a. The the coagulation section 18b and the cutting section 18a integrally forming electrode member 18 may during a coagulation process over the entire surface area, that act both on the surface area of ​​Koagulationsabschnittes 18b as well as over the surface region of the cutting portion 18a, as a coagulation electrode, while the tapers formed cutting portion 18a alone is a later cutting available. For the cutting operation, it is provided that the cutting portion 18 a cutting current is supplied, which is different to the coagulation current.

If the cutting portion 18a ge as an edge with a triangular cross-section. formed Fig. 1, the smooth transition from a large area to the edge-shaped taper in particularly, the entire electrode part 18 with adequate tissue thickness allows use as a coagulation and 18a to be used in an advanced operational stage, the cutting section alone for cutting.

If the cutting portion is formed 18a as an edge having a circular cross-section at said at least one electrode part 18 as shown in Fig. 2, so there is a relatively large electrode area for the coagulation available during formed as an edge cutting portion 18a with a sufficiently large tissue thickness hardly into weight falls. During the further course of operation, compared with cherish Direction in sufficient proximity electrode parts 18, 19 of the electrosurgical instrument 10 that a cutting operation can be ermöghcht 18a increase the current density in such a way, due to the edge-shaped configuration of the cutting portion.

In a according to Fig. 3 is substantially spherical in shape to the at least one electrode portion 18 formed cutting portion, the cutting surface 18a can be kept larger, and carry a correspondingly wider section.

Moreover, the cutting portion 18a, 19a and Lacy, needle-like or be formed like a loop.

Fig. 4 shows an electrode arrangement in which the cutting portion 18a, 19a respectively formed on the opposite cherish electrode portions 18, 19 is. This means that even here at both electrode parts 18, 19 explicit Koagulationsabschnitte 18b, 19b. Even this figure is ledighch be understood schematically. Due to the designed for cutting portions 18a, 19a is a particularly precise

Cutting effect achievable because the current density at both electrode parts 18, can be raised 19th

Fig. 5 shows a functional block diagram, wherein the electrosurgical instrument 10 is connected to a high frequency surgical apparatus 60. Here, exclusively, and thus schematically shown which are essential for explaining the invention components of the HF-surgery device 60th

The electrosurgical unit 60 has an input terminal 63 for example for Anschheßen of actuators, such as fingerprints and / or foot switch (not shown) for activating and / or deactivating the high frequency current on. The actuators can be realized here preferably via a computer arrangement and are (not shown) in practical use by a control unit connected to a HF generator 61st For simplicity, the input terminal 63 is connected in this representation directly with the RF generator 61 and therefore shown with a dashed line. a first output terminal 64 and a second output terminal 65 are provided on the output side to the HF-surgery device 60 via the electrosurgical instrument 10 is connected. The core of the HF-surgery device 60 of the controllable HF generator 61 is, more specifically, for generating a high frequency current, for generating a voltage U HF. By adjusting the voltage U HF can the desired current strength I HF for the various operating modes, such as coagulation or cutting set. The RF generator 61 is connected to a control unit 62nd The control unit 62 is configured to receive signals from switching means 50, which are disposed on the electrosurgical instrument 10th

The switching devices 50 are of the electrosurgical between branches 11, 12

arranged instrument and detecting a threshold value, z. B. as a defined distance between the branches 11, 12, ie between the electrode parts 18, 19. The distance between the electrode parts 18, 19 serves as an indication that a cutting operation can be carried out and is on the level of the adjusted RF voltage tuned. Once a certain distance by the bringing together of the sectors 11, 12 is reached, are operated, the switching devices 50 and send a signal to the control unit 62 on. This then causes the feeding of the corresponding cutting current through the RF generator 61 via the proximal ends 15, 16 of the electrosurgical instrument 10 to the respective cutting sections 18a, 19a. It should be noted that the cutting portion may also be formed only at one or at both electrode parts 18, 19th For the following explanations will angenmommen that both electrode parts 18, 19 a cutting portion 18a having 19a.

To detect the distance and for activating the controlling the cutting current

For the exact arrangement of the switching devices 6 and 7 refer to the description of FIG. Directed. The detection of the threshold value is for example also via a control unit 62 associated with means (not shown) for resistance measurement. Once in the tissue, a defined resistance is achieved due to the operation path, causes the control unit 62 that the jeweihgen cutting section 18a, 19a of the respective cutting current is supplied. The threshold value is accordingly detected as ohmic resistance of the tissue.

It is also possible to assign the control unit 62 an arc monitor and / or a current monitor (not shown), which detect the threshold value as optimal Koagulationsendzeitpunkt. The cutting current is then fed to at least the cutting portion 18a jeweihgen 19a, once the coagulation is terminated due to the geheferten from the corresponding monitor signal. In order for the supply of cutting current is advantageously an ideal for the course of the operation time. The operations of the current monitor and arc monitor are described for example in EP 0253012 Bl detail.

Fig. 6 shows an Sc hnittansicht along the line VI -. VI of Figure 7 of an electrode arrangement in a fifth embodiment. Fig. 7 shows a side view of the electrosurgical instrument 10 according to FIG. 6. The electrosurgical instrument 10 is designed here as a tweezers-like instrument.

In FIGS. Distal ends 13, 14 of the limbs 11, 12 of the electrosurgical instrument 10 are depicted, as well as respective electrode portions 18, 19. As in particular Fig. 7 can be seen, is within a sector 12, a two-armed lever 30 having a first end 31 mounted and a second end 32 about a rotation axis 34 rotatably, wherein the first end 31 for receiving the cutting portion 19a and the second end 32 is provided for contacting the opposing branch 11 or provided on the opposing branch 11 spacer 20th The lever 30 serves the positioning of the cutting portion 19a, so that it is movable relative to the envisaged for the coagulation section 19b. That is, in this embodiment, the electrode portion 19 of two independent portions, the coagulation section 19b and the cutting portion 19a is formed. For receiving the lever 30 in the branch 12, this has a recess 21, in which the lever 30 is preferably completely countersunk at its first end 31st The recess is formed in both the coagulation section 19b of the branch 12 and in the branch 12 itself. By Möghchkeit dumping, the cutting section 19a of impaired coagulation 19b during coagulation by the cutting portion 19 is avoided.

In merging the branches 11, 12 by the operator is a continuous approximation of the spacer 20 to the second end 32 of the lever 30 takes place, the second end 32 has a bearing surface 33 in this embodiment. As soon as the

Spacer 20 comes into contact on the opposite branch 11 with the bearing surface 33, the first end 31 of the lever 30 lifts out of a rest position from the sector 12, so that the cutting portion 19 projects beyond the coagulation electrode 19b. The cutting section 19a and the gegenüberhegende electrode part 18 can now interact in a cutting phase. The spacer 20 or the bearing surface 33, therefore, have the switching means 50, as already described in detail above. By contacting the spacer 20 and the bearing surface 33 with the switching means 50 can then be upon the actuation of the corresponding cutting current via current-supply means 17, as also described above, to perform the cutting section 19a.

In the lever 30 receiving branch 12, a spring element 40 is provided. This is connected at a first end 41 of the branch 12 and at a second end 42 to the second lever end of the 32nd By contacting the support surface 33 of the second lever end 32 with the spacer 20 of the opposing branch 11, or with the disposed on the spacer 20 or the bearing surface 33 switching means 50 which attached to the second lever end 32 of spring 40 is such. B. a coil spring compressed. Once the contact is interrupted, the spring 40 the lever 30 in its rest position, so that the lever end of the cutting section 19a having sunk in the sector 12 31st Thus the coagulation 19b would be back for a coagulation available. The spring element 40 is an easy-to-install and cost-effective component that always delivers hardly susceptible to wear the required function. The switching devices 50 can be placed 12 the remainder in other parts of the branches 11. Especially non-contact switch would offer then that forward a signal to the control unit when a defined distance between the electrode parts 18, 19 even without direct contact.

The first end of the two-armed lever 31 may include a receiving device for the cutting portion 19a, so that it is removable from the electrosurgical instrument, for example for cleaning purposes easily. Alternatively, it is possible to form the first end of the lever 31 integral with the cutting portion 19a. So an extremely inexpensive device can be manufactured.

Because of the simple mechanics of the positioning device 30 just described for the cutting portion 19 a multifunctional electrosurgical instrument 10 is produced in a simple and cost effective manner.

The cutting section 18a, 19a can preferably with an anti-adhesive coating and / or with a layer of erosion-resistant material formed. Making it possible to avoid burning of tissue or the wear of the cutting portion.

In Fig. 8a shows a typical curve of the current strength of the RF current is shown as a function of different operating modes. On the ordinate axis is the current I HF, on the abscissa axis the time t is plotted. FIG. 8b shows the on Fig. 8a corresponding voltage-time diagram. On the ordinate axis is the voltage U HF at the

Abscissa axis represents the time t is again applied. Since this is in both diagrams is a schematic representation of the units are not listed.

According to a coagulation mode is Fig. 8a at a time t, turned on, the current starts to flow through the tissue to be coagulated. Due to the heating of the tissue, the current I HF rises up to a time T 2. From the time t 2, the tissue begins to coagulate, that is a vapor phase begins. Due to the induced by the RF current heat build a defined region of tissue by protein coagulation and dehydration can be changed or destroyed. The vorhegenden in the sol state colloidal tissue components go there first in the gel state, with the now gelatinous tissue components anschheßend further condense with elimination of liquid; overcooked the tissue. The resistance of the fabric increases accordingly, so that the current I HF due to decreasing conductivity of the tissue decreases to a time T3. Has reached a certain stage, the drying of the tissue coagulation stops. Between times t 3 and t 4, a cutting mode. The figure here shows a relatively constant course of the current strength due to the ^ essentially constant tissue resistance during the cutting operation.

Referring to FIG. 8b a certain voltage UHF is set at the RF generator for the period of time t j to t 3. The following coagulation of the cutting mode requires an increase in this voltage UHF between times t 3 and t. 4 The time required for the cutting current IHF is ultimately dependent on the set voltage UHF and from the tissue resistance of the already koaguherten tissue. At time t 4, the cutting mode can, for example, ended by an automatic switch-off device.

It should be noted that all the parts described above are seen on its own and claimed as essential to the invention in any combination, especially the details shown in the drawings. Amendments to this are familiar to the expert.

LIST OF REFERENCE NUMBERS

10 electrosurgical instrument

11 clamp part, industry

12 terminals in part, industry 13 Distal end

Distal end 14

Proximal end 15

Proximal end 16

17 current-supply means Elektrodenteila cutting portion Schneidelektrodeb coagulation section, coagulation Elektrodenteila cutting portion Schneidelektrodeb coagulation section, coagulation spacer recess two-armed lever positioning means first end of the lever second end of the lever support surface rotation axis spring member first end of the spring element second end of the spring element switching devices electrosurgical unit radio frequency generator control unit input terminal first output terminal second output port

Claims

claims

1. An electrosurgical instrument with two pivotally interconnected sectors (11, 12) which are operable to open or Schheßen according to a clamping, spreading or cutting tool, - electrode parts (18, 19) at distal ends (13, 14) of the branches (11, 12) for grasping tissue and for conducting a coagulation current through the tissue to coagulation thereof, which are electrically insulated from each other, current-supply means (17) for feeding the coagulating current to the electrode parts (18, 19), characterized in that at least at an electrode member (18, 19) is laid out as a cutting electrode, the cutting portion (18a, 19a) is formed so that the electrode member (18, 19) the cutting portion (18a, 19a) and a coagulation section (18b, 19b) and - a control unit ( 62) is provided to control the RF current such that characteristic properties of the detected upon reaching a threshold minimum tissue d em cutting portion (18a, 19a), a cutting current is supplied, which is unterschiedhch for coagulation.

2. An electrosurgical instrument according to claim 1, characterized in that the control unit (62) switching means (50) are associated with the threshold value as a defined distance between the branches (11, 12) sense, so that the cutting current is supplied depending on the distance ,

3. An electrosurgical instrument according to claim 1 or 2, especially according to claim 2, characterized in that the switching means (50) to at least one of the branches (11, 12) and / or arranged on an at least on one of the branches (11, 12) spacers (20) are provided.

4. An electrosurgical instrument according to any one of the preceding claims, in particular according to claim 2 or 3, characterized in that the switching means (50) are formed as a push-button switch.

5. An electrosurgical instrument according to any one of the preceding claims, in particular according to one of claims 2 to 4, characterized in that the switching means (50) are constructed as non-contact switch.

6. An electrosurgical instrument according to any one of the preceding claims, in particular according to claim 5, characterized in that the non-contact switch as a proximity switch or a reed contact are formed.

7. An electrosurgical instrument according to any one of the preceding claims, characterized in that the control unit (62) is associated with a device for resistance measurement which detects the threshold value as the ohmic resistance of the tissue so that the cutting current is supplied depending on the ohmic resistance becomes.

8. An electrosurgical instrument according to any one of the preceding claims, characterized in that the control unit (62) is an arc monitor and / or current monitor are assigned, which detect the threshold value as optimal Koagulationsendzeitpunkt, so that the cutting current is supplied depending on the Koagulationsendzeitpunktes.

9. An electrosurgical instrument according to any one of the preceding claims, characterized in that the cutting section (18a, 19a) of the at least one electrode member (18, 19) as a with respect to the coagulation section (18b, 19b) of the at least one electrode portion (18, 19) a tapered portion is formed.

10. An electrosurgical instrument according to any one of the preceding claims, characterized in that the cutting section (18a, 19a) is formed as an edge with a triangular cross-section Wesenthchen the at least one electrode member (18, 19).

11. An electrosurgical instrument according to any one of the preceding claims, in particular according to one of claims 1 to 9, characterized in that the cutting section (18a, 19a) is formed as an edge with a substantially circular cross-section of the at least one electrode member (18, 19) ,

12. An electrosurgical instrument according to any one of the preceding claims, in particular according to one of claims 1 to 9, characterized in that the cutting section (18a, 19a) in Wesenthchen spherical on the at least one electrode member (18, 19) is formed.

13. An electrosurgical instrument according to any one of the preceding claims, in particular according to one of claims 1 to 9, characterized in that the cutting section (18a, 19a) peak, acicular or formed in loops.

14. An electrosurgical instrument according to any one of the preceding claims, characterized in that the cutting section in each case on opposite electrode parts (18, 19) (18a, 19a) is formed.

15. An electrosurgical instrument according to any one of the preceding claims, characterized in that the cutting section (18a, 19a) by means of positioning means (30) relative to the coagulation section (18b, 19b) is movable part formed on this.

16. An electrosurgical instrument according to any one of the preceding claims, in particular claim 15, characterized in that the positioning means is mounted a rotatably in one of the branches (12) two-armed lever (30) having a first end (31) and a second end (32) , said first end (31) for receiving the cutting portion (19a) and the second end for contacting the opposing branch (11) or on the opposing branch (11) arranged spacer (20) is provided so that when contact the cutting portion (19a) is movable in the direction of the opposite cherish applying electrodes part (18), having a restoring device (40) so that the cutting portion (19a) after completion of the contacting is moved back into the starting position.

17. An electrosurgical instrument according to any one of the preceding claims, in particular according to claim 15 or 16, characterized in that the first end (31) of the lever (30) is attached to a receptacle device for the cutting portion (19a).

18. An electrosurgical instrument according to any one of the preceding claims, in particular according to claim 15 or 16, characterized in that the cutting section (19a) as an integral part of the first end is adapted (31) of the lever (30).

19. An electrosurgical instrument according to any one of the preceding claims, in particular according to one of claims 15 to 18, characterized in that the restoring device (40) than in the Positionierungseiήrichtungen (30) having sector (12) arranged spring element is provided.

20. An electrosurgical instrument according to any one of the preceding claims, characterized in that (18a, 19a) is formed of a non-stick coating and / or from erosion-resistant material of the cutting portion.